routes inside the vCenter Server Shell. There is two ways to do that. One method is using "route add" command on shell access. For example:

# route add -net 10.10.10.0 netmask 255.255.255.0 gw 10.10.100.1 dev eth0 

Result of this method is not persistent and will be clean after VCSA restart, Then it's useful only for testing or temporary situations. But if you want to save it, the Second way is editing of file *.network (such as 10-eth0.network) in and path "/etc/systemd/network" add intended routes in this form:

[Routes]

Destination=10.10.20.0/24

Gateway=10.10.100.2

Remember to add each route line in separated [Routes] brackets, otherwise it's not working as you expected. Then restart the network interface:

# ifdown eth0 | ifup eth0

or restart the networkd with these commands:

# systemctl restart systemd-networkd

# service network restart

And now if you want to check the results, run:

# route -n

# ip route show

https://3.bp.blogspot.com/-zfytKM3RkKQ/XERCGUlM0tI/AAAAAAAABco/qwuJmexLQhYY_s62eorOJbjNke07TNbrgCEwYBhgL/s1600/routes-list.PNG

Without shell access if you only login to VCSA console, there is many CLI for routing check and config, so you can use of these. To check them and how to use:

> routes.list --help

> routes.add --help

> routes.delete --help

> routes.test --help

Note I: There is another file here: "/etc/sysconfig/network/routes", if you view it's content, it will show only the system default gateway, no more routes will be shown here.

Note II: If you want to add routing to your ESXi hosts, just do:

# esxcli network ip route ipv4 add -n 10.10.20.0/24 -g 10.10.100.2

 

Source of content inside my personal blog: Undercity of Virtualization: Set Manual Routing for VCSA